1. Field of the Invention
The present invention relates to the structure of an IC card and more particularly, to the structure inside an IC card.
2. Description of the Related Art
FIG. 7 is a perspective view of an IC card 1; FIG. 8 is a plan view of a conventional substrate incorporated into the IC card of FIG. 7 and FIG. 9 is a cross-sectional view taken along line 9--9 of FIG. 7. A plurality of electronic components 3 are installed on the obverse and reverse surfaces of a substrate 2. The electronic components 3 are connected to circuit patterns 2b on the obverse surface of the substrate 2. A caulking hole 2a is located at the center of the substrate 2. A connector 6 includes a plurality of external connecting terminals 6a which are separate from the substrate 2. The external connecting terminals 6a, each linked to the circuit patterns 2b on the substrate 2, electrically connect the electronic components 3 on the substrate 2 to the outside of a housing.
The substrate 2 and the connector 6 are supported by the inside of a frame 4. FIG. 9 shows how the substrate 2 is supported by the inside of the frame 4. A support 4a extends through the center of the frame 4 from one end of the inside of the frame 4 to the other and in a direction at right angles with line 9--9 of FIG. 7. The support 4a is provided to a caulking portion 4b at the center thereof. The substrate 2 not only is supported by the support 4a and supporting portions 4c at both ends of the frame 4, but also is fixed to the inside of the frame 4 by caulking with the aid of the caulking hole 2a and the caulking 4b. The connector 6 is also supported by the inside of the frame 4. The portion of the frame 4 to which the connector 6 is attached is shaped so that the connector 6 can fit into it. For example, a sub-frame (not shown) presses the connector 6 in place downwardly, thus fixing it to the inside of the frame 4 in such a way that the sub-frame is mated with the inside. The illustrations of these portions are omitted.
Panels 5a and 5b are bonded by an adhesive or the like to the obverse and reverse surfaces of the frame 4, respectively. The substrate 2, together with the connector 6, is accommodated in a housing composed of the frame 4 and the panels 5a and 5b. The panels 5a and 5b are usually made of metal in order to protect the electronic components from static from outside the IC card, a magnetic field, physical external force, and the like.
Because of the thus-constructed conventional IC card, electronic components can be installed merely on both surfaces of the substrate. Since electronic components can be installed only to the extent that the substrate can accommodate them, the number of electronic components to be installed is limited.